This project develops new statistical methods for epidemiology with broad applications and also methods as needed for ongoing projects in epidemiology, particularly those related to reproductive studies. The work this year involved eight main projects. (1) A project that is collaborative with David Umbach, Min Shi and Katie O'Brien proposed improved methods of adjustment of concentrations from pooled specimens for creatinine (if urine) and for serum lipids (if serum). (2) In studies of neonatal mortality both the fetuses at risk approach and the classical approach based on live births can lead the inference astray. (3) In work that is joint with Shanshan Zhao we have developed improved risk prediction models that account for family structure and breast cancer history and we are applying them to data from the Sister Study on incident breast cancer. (4) Work is continuing related to mediation analysis in scenarios where the exposure interacts with a mediator. (5) We are developing methods for aggregating information from pregnancy history data for use in risk models, e.g. occurrences of gestational diabetes in relation to later risk of chronic diabetes. (6) I developed an improved approach for adjusting for induced abortion as a competing risk in studies of spontaneous abortion. (7) We are developing methods for assessing the heritability of a tendency to multiply ovulate, based on exploration of the Norwegian Medical Birth Registry data. (8) We are developing methods for assessing evidence for heritability of age at diagnosis and applying those methods to data from the NIEHS Sister Study.